WIND ann WATER-SPOUTS, &. 339 
pointing is owing to the courfe of the air, as the bend is 
to, two different ones at different heights. 
The next thing propofed to be confidered, was the 
great roar that attends a complete fpout while it lafts; and 
it is the fame as that in cataracts or falls of water from 
great eminencies. This kind of roar could not exift in any 
way of afcent, being very different from that of a whirl- 
wind, which is no other than that of any other ftrong wind. 
Mr. Stuart’s figures of the great fpouts are drawn with 
the appearance of a bufh round their bafes: The cafe is 
fuch, that great falls of waters muft make a proportion- 
able fpray; {fo that the appearance is natural, and indeed 
a neceflary confequence. It rifes up from the foot of the 
fpout and falls back in a parabolic manner into the fea. 
As was faid of the roar juft now, fo it may be faid of this, 
that it could not have exifted in any conceivable way of 
afcent; while on the contrary it is perfectly agreeable to 
nature on the principle of defcent. It continues the whole 
time of a large fpout, increafing and diminifhing as that 
does. . 
The appearance of a break or partition in the trunk of 
the {pout, at the top of the bufh, is a very curious phe- 
nomenon : It is not real but apparent, and could not have 
happened without the bufh; it being caufed by a refrac- 
tion of rays from the drops that conftitute the top of the 
bufh; whence a divergency and fo much lofs of vifion. 
In great fpouts there is alfo a pillar-like appearance, be- 
ing a part of the trunk within the bufh, and by another 
refraction through the fide of the bufh ; by which it ap- 
pears much bigger than it is, and limited in altitude by 
the break. The three laft are agreeable to the laws of 
optics; and all the five particulars being attendants on the 
greater or the {maller fpouts, are to me undeniable evi- 
dences of the univerfal defcent of waters in thefe bodies. 
I pafs from Mr. Stuart’s figures to that of Mr. Maine, 
which is not lefs curious. 
Mr, 
